1. Field of the Invention
The present invention relates to a finisher and a sheet punching/stapling method, and more particularly, to a finisher which has a function of punching a sheet ejected from an image forming machine and a function of stapling sheets, and a punching/stapling method in the finisher.
2. Description of Related Art
Recently, various types of sorters (finishers) for handling image-formed sheets have been developed as optional attachments for image forming machines, such as copying machines and printers. Further, some types of sorters have a stapling function and a punching function as well as sorting function.
When sheets are punched and stapled, if a staple is hit into the sheets inside of punch holes (at a point closer to the center of the sheets than the punch holes), there will occur inconvenience due to the constraint of the staple after filing of the stapled sheets by fastening the sheets through the punch holes. For example, it is inconvenient to turn pages while the sheets are filed, and if turning pages by force, there is a fear that the sheets will be torn at the point where the staple is hit.